Armor-plate.



R. A. HADPIELD. ARMOR PLATE. APPLICATION FILED MAR.31, 1909. RENEWED we. a, 1913.

1,089,638. Patented Mar. 10, 1914,

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preferably made of nickel-chromium steel To all 1071 cm it may concern lines of weakness in the armor.

'strueted with armor built up of' plates or UNITED strnpns PATENT OFFICE.

. ROBERT ABBOTT Hanfernnn, or SHEFFIELD, nuenann.

Annex-Prisms.

- Specification of Letters Patent. Patented lIar. 10, 1914.

Application filed March ,31, 1909, Serial ll'o. 48?,041. Renewed August 5, 1913. Serial No. 783,412.

Be it known that I, ROBERT ABBOTT HAP FIELD, a subject of the King of Great Britain, residing at Parkhead House, Sheffield, in the county of York, England, have invented new and useful Improvements in ArmonPlate, of which the following is a specification.

In battleships and like armor clad ships, the armor is at present built up of a number of rolled or forged steel plates each of which is usually of uniform section through out its depth. The manufacture of such plates involves long, difficult and costly operations and where such plates have to be made of curved shape or of taper section for part of their depth, as is sometimes required, this adds considerably to the difficulties and cost. Furthermore, such armor plates can only be produced practically of such dimensions that at least two of them placed vertically edgewise one on the other are necessary to obtain the full depth of armor required, so that great care and much labor is required insecurely holding the plates in position and the resulting armor contains in addition to vertical joints many horizontal ones which result in additional Now the present invention has for object to provide a battleship or like armor clad vessel (hereinafter referredto as a battleship) with armor that shall offer very great resistance to penetration and fracture, which can be constructed and applied in a quicker, cheaper and more effective manner than the rolled or forged armor heretofore employed, and the several sections of'which can be readily made of any desired section to allow of the material being disposed to the best advantage to resist attack with the minimum of weight, and of any desired curvature to suit the different parts of the battleship to which they are to be applied, and which can be made of such superficial dimensions as to avoid the presence in the armor built up of such plates of any horizontal lines of division or joints. To this end, according thereto, a battleship is consec ions of steel orsteel alloy, such as nickel steel and nickel chromium steel that'is capable of being cast to the desired shape and of offering great resistance to perforation and fracture. The plates or sections are 1 Limited, of Sheffield,

had to the resistance which its alloy of the kind known as Era steel, as

made by Hadfields Steel Foundry Company such steel having substantially the composition set forth in the specification of British application for Letters Patent No. 586% of 1908. The steel is cast in molds having internally a formation such as to produce flat or curved armor plates of the required dimensions with, when necessary, holes, recesses, project-ions, brackets or equivalent for engagement of the bolts or other fastening devices used for holding the plates in position on the sides of the ship. Such armor plates can readily be made of different thicknesses at difierent parts thereof, where this is necessary, so that the metal can be disposed in the most advantageous manner to resist attack and thereby enable an effective plate to be ,roduced of the minimum weight,

different parts are required to offer. Thus, the armor plates, or some of them, on a battleship according to this invention can be made of varying thickness in the direction of their depth, their central portions for example being of greatest thickness and their upper and lower portions of gradually diminishmg th ckness from the central portion.

My invention 18 shown in the accompany ing drawing in. which the reference characters of the description indicate corresponding parts in the different views.'

Figure l is a face view of a plate made in accordance with my invention. Fig. 2 is a vertical cross sectional view thereof. Fig. 3 illustrates in cross section a modified forn of my invention and Fig. 4 shows in .elevation the employment of an armor belt made in accordance with my invention.

In the drawing there is shown Fig. 2) an armor plate of the kind referred to having its central portion a of greatest thickness v and its upper and lower portions a and a of described have/been j produced having a. depth u to between thirteen and fourteen regard being feet, a length up to twenty two feet, and of varying thickness, the weight of such a plate varying up to fort four tons in the case'of a plate thirteen eet ten inches in depth,

twenty two feet in length, a thickness of ten 'inches at the central portion tapering to a:

thickness of four inches at the top edge and a thickness of two inches at the bottom edge. Such armor plates are or may advantageously be made of such depth, as indicated, that when applied side by side to a battle ship, as shown for example in Fig. 4, they will each extend the full depth of the requiredarmor, or of the main portion of the required armor, of the ship, so that the armor, or the main portion thereof, will, be composed of vertical sections only, separated by vertical division lines or joints, allhorizontal division lines or joints, at least in the main portion of the armor, being thereby, avoided.

. I r Each armor plate 1s or may advantageously be subjected to a special heat treatment consisting in subjecting it to successiige heating and cooling operations for the purfore described, may be face hardened by bedding that side ofthe plate which is not.

to be hardened, in sand on a furnace bottom, placing carbonizing material upon the intermediate portion of the other or upper surface of the plate that is to be face hardened and protecting the end portions ofsuch surface as by fire bricks or other refractory material. The side of the plate covere with the carbonizing material is then heated to a high temperature for a suflicient time to eifect carbonizationthereof to the desired extent, and after this process is complete, the plate is quenched by water or other cooling medium either all over its surface or at that part only which has been carbonized, such quenching being done either immediately after the carbonizing. process is finished, or after the plate has been subjected to the special heat treatments hereinbefore mentioned. In the latter case, the plate, after quenching, may be taper heated and again quenched,-also in the main ner described in the said, former specification. In this way armor plates can be produced in which the carbonizing effect will be greatest at the central portion of the plate and taper off to nothing at the upper and lower ends so that they will be face hardened at the principal portion where such hardening is required and be very tough at the upper and lower ends, as well as at the back of the plates. Such armor plates, whether of uniform or taper section, constitute a special feature of the invention.

By means of the present inventionbattleships can be built in a stronger, quicker and much cheaper manner than these constructed with forged or rolled armor plates as heretofore.

Having now particularly described and ascertained the nature of the said invention and in what manner the same is to beperformed, I declare that what I claim is 1. An armor belt for battleships composed of a plurality of steel plates made of suflicient depth toextend the full depth of has'vertical divisional lines only, said plates being formed of gradually diminishing thickness from their central portion.

2. A battleship having an armor belt composed of cast nickel, chromium, steel alloy plates, said plates beingheat'treated to produce hardened central face portions, and having toughened end ortions.

A 3.. In an armor belt or battleships, composed of a plurality of steel plates the interbeing carbonized and face hardened at its central portion and the carbonizin and hardening effect tapering off to nothmg at the upper and lower ends so that the plate will be face hardened at its central portion ends as well as at theback t ereof, substantially as described. I i 4. A battleship provided with armor built up of plates composed of Era steel cast to shape and of different thicknesses in the direction of their depth, such plates being heat treated, having hardened central face portions and toughened end portions and of such depth that the each extend the full depth of the require 'armor,.or of the main po'rtionof the required armor, of the ship, substantially as described. 7 v

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses,

ROBERT ABBOTTJHADFIELD. Witnesses:

WILLIAM, Onoss, WILLIAM CRAWLEY.

and be very tough at the 11 per and lower the required armor-belt so that the said belt 1 mediate portion of one side of each plate 

